“Is That A Inverted Gravimetric Universe Or A Temporal Neomorphic Universe?”

Fair use, https://en.wikipedia.org/w/index.php?curid=2120652

H2G2 casts a long shadow. Any radio science fiction comedy is bound to draw comparisons with it, and even more so if it’s on Radio 4. To some extent, the same problem exists on BBC television, where SF comedy is likely to be compared to ‘Red Dwarf’. This happened with the rather obscure ‘Hyperdrive’ with Miranda Hart, Nick Frost and Kevin Eldon, which ran for only two series. It wasn’t wonderful to be sure, but it was absolutely not a rip-off of ‘Red Dwarf’. It was ‘The Navy Lark’ in space. That series, of which I was never a fan but you know, it was okay, was probably unknown or forgotten by 2005 but is so much more similar to ‘Hyperdrive’ than ‘Red Dwarf’, and if people had known about that and resisted the urge to draw comparisons with the most prominent space comedy, I’m sure it would’ve been perceived much more positively.

There have been quite a few Radio 4 SF comedies since 1980, and H2G2 is rather like the Beatles in that it defined a genre and cannot be successfully imitated without being seen as derivative. What, then, do you do if you want to write a series of this kind? It has to be completely different from Douglas Adams’s work, and probably use a different kind of humour, and this is very restrictive. However, restriction is a wonderful spur to creativity and originality if you can dislodge your focus sufficiently on what you’re trying not to write. I would say Tony Bagley’s ‘Married’ has successfully escaped from Mr Different Adams’s fierce gravitational pull and managed to write something pretty fresh. I mean, he did it over twenty years ago now but it’s still good.

The premise of ‘Married’ (SPOILERS) is that steadfastly single and misanthropist architect Robin Lightfoot wakes up one morning to find himself in a parallel universe where he’s married with children and works at a greetings card company, and absolutely hates his new life. Meanwhile, his counterpart in the parallel universe has entered this one and proceeds to trash his life, since he too is misanthropic but considerably more actively antisocial and abusive. The series becomes increasingly surreal and science-fictiony as it proceeds until the existence of the entire Multiverse is threatened and the fabric of reality breaks down. Robin finds a solution in the final episode, but it isn’t clear if the Multiverse is saved.

Robin is played by Hugh Bonneville, cast somewhat against type. Arthur Smith is another central character, who plays himself, and Julian Clary makes a guest appearance. Many people who exist in this universe also exist in the other, but often have different life histories. It gently breaks the fourth wall a number of times. The only person with an initial grasp on the situation is his son, who reads a lot of graphic novels and is therefore savvy about parallel universes. In a sublime piece of technobabble, he explains to Robin that there are two types of parallel universe, Inverted Gravimetric and Temporal Neomorphic. It’s never at all clear what these are but they sound marvellous.

Although the drama centres, initially at least, on the interaction between the characters, the background is also intriguing. Much of it is based on the humour of rôle reversal. Tony Blair is leader of the Conservative Party. Environmentalists are campaigning for the legalisation of genetically-modified organisms and the use of organophosphate pesticides. Most people believe Francis Bacon wrote the plays usually attributed to Shakespeare. Jimmi Hendrix is a middle-of-the-road radio disc jockey. ‘The Guardian’ is a tabloid and has a porn page but ‘The Sun’ is a quality newspaper. There were eighteen years of Labour rule up to 1997, when the Liberal Democrats achieved power, led by Richard Branson, who is now Prime Minister. Alcohol is a Class A drug but you can buy Cannabis over the counter in Boots. There is no Sunday trading. Surrey is a deprived area but the northeast of England is affluent.

The humour is not confined to reversals. Fashion is how it was in the early 1970s, with kipper ties and flares. Richard Whiteley did something nebulous but awesome in the “Fuel Crisis of ’89” which has made him a universally-loved national hero and there are statues in his honour. Margaret Thatcher died in 1978. The death penalty is not only still in place but fast-tracked without appeal to avoid causing prolonged suffering to the perpetrator. Edward VIII didn’t abdicate and was replaced by Richard IV and then John II, who leaves his wife and comes out as gay, marrying his lover Adrian. He is of course played by Julian Clary. Janis Joplin is still alive. There’s no Marks & Spencers but instead there’s a Marks, Bruce & Willis. There’s a Channel 6. Radio 4 is called Radio 1 and there’s also a Radio 4 Live. The Today programme doesn’t exist. Nicholas Parsons presents a radio panel game called ‘The Transport Quiz’, which seems to be a reference to Mornington Crescent and ‘Just A Minute’. Kingsley and then Martin Amis read the Shipping Forecast. The Titanic wasn’t hit by an iceberg but was torpedoed in 1940. There are numerous other examples, all mainly for the sake of humour. They don’t particularly feel like they go that deep but they are fun.

I’m stuck with my usual quandary here of not knowing how well-known this is. I first came across it when its final episode was broadcast some time in the ‘noughties, and remarkably, if you know the ending, I seem to remember being in the bath at the time. This makes me wonder about false memories. I didn’t catch up with the whole series until about 2007.

Most of all, I wonder about the model of the Multiverse being used in the series. The real answer is “whatever makes the listeners laugh” of course, but those two terms, “inverted gravimetric” and “temporal neomorphic” have a real ring to them. Swapping the first words of each gets you “temporal gravimetric” and “inverted neomorphic”. The former is a real phrase, often used to refer to the measurement of subterranean water and its fluctuation. Temporal gravimetry is the measure of mass changes through time, so it is an actual thing but nothing to do with parallel universes. Inverted gravimetry is no closer. Neomorphism is to do with metamorphic change in rocks and is also a variety of gene mutation where a newly formed gene becomes manifest immediately rather than being masked or inactive.

These parallel universes are more like the “mirror Universe” of ‘Star Trek’ than the bog-standard “choose a pivotal point in history and change it” approach of alternate timelines. Like the Mirror Universe, the same people tend to exist in various universes, so they can’t be based on events which prevent people from existing or cause people to come into existence. They’re interdependent. Ultimately this becomes apparent in other ways, and it raises the question of whether the only kind of parallel universe is one which deviates in connection with events occurring within it. David Lewis’s idea of modal realism is easily confused with the idea of alternate timelines and quantum-related universe variations, but could in fact be an entirely different beast. We talk as if things could be other than they are. We say “if I were you, I wouldn’t do that” for example, but in fact that isn’t true because someone cannot be someone else and they just would act in that way. There is also the issue of paradoxes of material implication. Material implication is usually understood to mean “if P then Q”, but in fact it means “not both P and not-Q”, which lacks the kind of “direction” implication normally implies, and it means that there are peculiar situations where, to quote Wikipedia, it would be true to say that if the Nazis had won the Second World War, everyone would be happy, because if something is false, it being true can imply everything, and if sonething is true, anything can imply it. The idea behind material implication is to make it impossible to move from true premises to false conclusions, meaning that truth implying falsehood is always false.

But a different history may not be the only way in which a world can be different. An alternate universe might be just one which is located elsewhere but exists in the same way as this one does, with nothing else in common except what must be so for it to exist meaningfully as a universe. This could mean being observed in some way, or at least having its existence deducible from something observable. Maybe this kind of multiverse is like a cluster of mushrooms whose stalks sprout from their Big Bangs and become mature as caps, but multidimensionally.

Robin describes the multiverse as like a loo roll. Each universe is a single sheet of paper, separated from its neighbours but also coiled up tightly, so that you could enter another universe on either side by travelling a long way and finding a portal, which is the paper between the perforations limiting the sheets, or, much more easily, you could move towards and away from the centre and enter a neighbour much more easily, since the other universes in those directions are but a whisker away, as thin as a single sheet of toilet paper or even less. Just as accidents can occur where you accidentally poke your finger through the paper, or the roll gets wet and water wets adjacent sheets and their contents might bleed through (assume it’s monogrammed toilet paper) like ink soaking through successive sheets, so can there be bleeding through or accidental penetrations into other universes, but because they’re “rolled up”, it’s easier to enter a universe five universes away or a different number, than it is to enter any of the neighbours in other directions. Isaac Asimov explored this idea in his ‘Cosmic Corkscrew’, a completely lost and unpublished story written in 1931 where a man discovers it’s possible to move forward or backward in time by a set interval because time is like the coils of a slinky, and on travelling forward a single loop of the coil, say a week, he finds the world has ended, and is unable to convince anyone on returning to his present and ends up in a mental hospital. There is of course absolutely no scientific evidence for this but it isn’t ruled out. There’s just no reason for supposing it to be the case. It does work quite well as a model though – it’s coherent. It’s easy to imagine each universe consisting of time and space, and then there being extra dimensions which link them together in different ways, so there are not only portals to adjacent universes separated by gigaparsecs but also extra dimensions in which other universes it would otherwise take countless æons to reach are only a hairsbreadth away, if only we could find our multidimensional equivalent of an inconvenient finger poke or splash of water.

Maybe. But what does “maybe” mean here? Using possible world semantics, “maybe” means “true in some possible worlds”. In other words it’s a bold statement that there are universes where this has been done, that there are bridges between universes which have either arisen spontaneously, through accidents or have been made on purpose. It can become very difficult to talk clearly about parallel universes because language like “possibly”, “probably”, “perhaps” and so forth then become references to places where this is actually so. “Probably” means “true in most possible worlds” for example, but if there are an infinite number of them, how can the majority of worlds contain such a situation? The ones in which the state of affairs doesn’t hold could also be infinite, so how is that a majority?

There are two very implausible things which never seem to get ruled out in spite of the difficulty in accepting how they are reasonable things to expect. One of them is travel backwards in time, and the other is parallel universes. In spite of the “cat among the pigeons” effect them being true would have on science, it remains unfeasible to rule either of them out.

That’s all.

Why Isn’t The Sun Red?

The first observation to be made here is that it’s likely that if the Sun was indeed red, or reddish, we probably wouldn’t see it that way, assuming we had colour vision. If the visible spectrum of the Sun peaked at the long end, the chances are that we would be relatively less sensitive to that colour, or, like many other mammals, completely lack the ability to see red at all, since it wouldn’t be very useful to us. On the other hand, there’s a different question arising from this, as follows: why is the Sun yellow? Why is it that human colour vision gives sunlight a golden tinge when one would expect that peak at yellow would be toned down for us to give us the impression that the Sun was white?

In fact I’ve never understood why people say sunlight is yellow. To me it’s definitely colourless, and in fact I think it has to be or most outdoor daylight scenes would have a yellow tinge, and they haven’t. I don’t really think I’m unusual in that. In fact I can’t see how any healthy human eye could fail to adjust to the appearance of daylight without coming to perceive it as neutral. Nonetheless, the Sun is a yellow dwarf, which marks the beginning of a mystery which has yet to be solved definitively and is related to the Fermi Paradox.

I’ll just briefly introduce the Hertzsprung-Russell Diagram:

By Richard Powell – The Hertzsprung Russell Diagram, CC BY-SA 2.5, https://commons.wikimedia.org/w/index.php?curid=1736396

This is probably one of those things not many people know about, but if it isn’t, sorry for boring you. If you plot stars by their absolute brightness and colour, you find that they’re not randomly distributed but tend to fall into particular categories. In particular there’s the Main Sequence, the line on the diagram our Sun is currently on and gradually moving towards the top right hand corner. This may be one reason why there was a major ice age around 700 million years ago, after most of the carbon dioxide had been cleared out of the air via photosynthesis, decreasing the Greenhouse Effect, and it’s also one reason Earth will be uninhabitable an æon from now.

The main spectral types (i.e. “colours”) of stars are classified by a series of letters: W, O, B, A, F, G, K, M, R, N and S. Of these, W, R, N and S are rare. There are thought to be only about fifty W-type stars in this Galaxy of 400 thousand million. They’re also known as Wolf-Rayet stars, hence the name, and are high in heavier elements and often surrounded by luminous clouds of gas. Interesting objects but nothing to do with what I’m talking about today. R- and N-type stars are cool and high in carbon, and S-types have roughly equal quantities of carbon and oxygen in their atmospheres, with zirconium monoxide. All of these are the “freak” stars. The main spectral types are O, B, A, F, G, K, and M, and in colour they are blue-white, blue-white, white, pale yellow, yellow, orange and red respectively. If you want examples of each, here you go: α Camelopardalis (the most distant visible star, actually in a different arm of the Milky Way from us), Rigel (the bright, bluish-white star in Orion), Sirius A and B, Procyon A, the Sun (and also α Centauri A), Arcturus (a fast star from outside the main part of the Milky Way which happens to be passing through our arm nearby at the moment), and of course Betelgeuse. Each spectral type is divided into ten subdivisions, numbered 0-9, and also into seven sizes numbered using Roman numerals, with the smallest at VII. Our Sun is a G2V-type star, or yellow dwarf.

The types of stars as far as age is concerned are called dwarfs, subgiants, giants, supergiants and hypergiants. For some reason there is no concept of an average-sized star. I don’t know why. Although the Sun is a yellow dwarf, it’s actually in the top 10% of stars by mass. You wouldn’t think this by looking at the sky though because many of the stars visible to the naked eye are blue giants. This has the side-effect of many of the stars routinely referred to in science fiction and space opera being the wrong ones. The hottest and most massive stars may form planets but don’t have time for life to evolve very far on them, and it’s also possible that their solar winds drive away the discs of gas and dust which would become planets otherwise, although on the other hand again, they may form small planets a long way away. Hence when ‘Star Trek’ talks about Rigel VII, some explaining needs to be done. Isaac Asimov once calculated that Rigel was visible over a seventh of the volume of the Galaxy, and a star that powerful is not likely to have habitable planets.

Smaller objects of a particular kind are likely to be more common than larger ones. Thus there’s more sand than pebbles on a beach and more pebbles than boulders. This is a general rule, and it applies to stars. Therefore the yellow dwarf, perhaps inappropriately named, we orbit is more massive than nine out of ten other stars, although there are some which are many times as large. Most known stars, including Proxima Centauri which is closest to the Sun, in the neighbourhood are red dwarfs, which are small, cool stars which will outlive the Sun many times over. Eleven of the twenty-seven stars within a dozen light years of the Sun are red dwarfs, and there may be more which are too faint to have been detected yet.

Criteria for habitability used to include the proviso that a star not be too small for a planet. Objects that orbit near massive other objects have locked rotation and constantly present the same face to their primaries or companions. For instance, we see Oceanus Procellarum, Mare Tranquilitatis and the other maria but we never see the far side of our satellite because it always faces us and therefore has a day lasting a whole month. It used to be thought that Mercury constantly faced the Sun and therefore was in constant sunlight on one side and constant darkness on the other, but in the 1960s this was found not to be so, although it does rotate only very slowly. A star less than seventy percent of the mass of the Sun would not be enough to warm Earth sufficiently at this distance for life as we know it to exist on the surface, and this planet would have to orbit so closely that it would, in fact, be like this, and for this reason it was long thought that life was impossible around smaller stars. However, this is only true to a certain extent. Although the orange, K-type stars in question do reach a point where Earth-like planets would have locked rotation of this kind and would therefore be completely uninhabitable, there’s a further point where the radiation from the star becomes weak enough for it not to heat the planet beyond bearable temperatures in its twilight zone. Such planets are called “eyeball planets” because of their appearance:

TRAPPIST-1f

The above is an artist’s impression of such a planet forty light years away in the constellation of Aquarius. It could conceivably have an ocean of water and habitable temperatures on its sunlit side with ice towards the terminator (the line between day and night) and of course a frozen solid dark side.

Not all red dwarfs are suitable stars for life-bearing planets because many of them tend to be flare stars. Barnard’s Star, Proxima, Wolf 359 and one of the UV Ceti binary system are all in this category. A flare star is a generally faint star which suddenly increases dramatically in visible brightness and other electromagnetic radiation, probably due to the release of energy in its magnetic field, making the conditions on its planets quite unstable. These are like solar flares but because the scale of the star is much smaller and the stars are much dimmer, they make a proportionately bigger difference to their output. This means they may not be so suitable after all. They can also become covered in many more sunspots than the Sun, which would reduce the radiation a lot, by up to forty percent. However, on the plus side they don’t suffer the catastrophic coronal mass ejections that the Sun occasionally does, meaning that planets are more likely to be able to hang on to their atmospheres, and it isn’t clear that red dwarfs are generally flare stars either. Some of them may be quite stable.

There are, as I’ve said, likely to be more orange dwarfs than yellow dwarfs, and more red dwarfs than orange or yellow dwarfs. Orange dwarfs, i.e. K-type stars, spend longer on the Main Sequence and evolve more slowly than yellow G-type dwarfs such as our Sun, so in a way the question could equally be, why isn’t the Sun orange?

Ten percent of stars are yellow dwarfs, but three-quarters are red dwarfs. If they were the same age as the Sun, only one in seven would need to be stable for them to have an equal chance of having habitable zones on their planets, all other things being equal (which they may well not be). However, red dwarfs stay in their current state for several times the length of the whole career of the Sun, whether or not it’s on the Main Sequence, and the smaller ones will last hundreds of times longer. Therefore it’s possible to use something similar to the Doomsday Argument here.

We evolved on a planet circling a yellow dwarf star, about eighty percent of the way through the time when it would remain suitable for life to be maintained here. The fact that it’s that late should already provide food for thought. However, there are seven and a half times as many red dwarfs as there are yellow dwarfs and they also last much longer, say ten times on average as a very conservative estimate, but in any case Barnard’s Star, for example, is twice as old as the Sun. Therefore, given that nothing else is relevant, and science relies on not making stuff up without a good reason, the probability that we would have come into existence during the Main Sequence lifetime of a yellow dwarf is only two percent. It also compares poorly with the orange dwarf scenario, though not quite as badly – it’s maybe about twice as likely that we would’ve evolved around a K-type star and the captured rotation problem cuts it down a bit.

Hence: why isn’t the Sun red? Why have we appeared in a system which is less common than the kind considered most likely to give rise to habitable planets? Also, why have we appeared so early in the history of the Universe? Barnard’s Star has had twice as long to have intelligent life forms evolve on one of its planets, assuming any are suitable. Maybe the answer to the Fermi paradox (where are all the aliens?) is that they haven’t evolved yet, and there will one day be many of them, but right now we are freakishly early and have appeared under a freakishly yellow star.

The principle of mediocrity evolved in connection with our growing perception that there was nothing special about who, where or when we are. China’s name for itself is 中國, the “Middle Kingdom”. Jain cosmology placed India at the centre of the flat Earth and Earth at the centre of an impressively large Universe. We refer to the sea between Europe and Afrika as the Mediterranean. Likewise, we used to think Earth was the centre of the Universe and that everything revolved around it. And so on. Then many of us were dislodged from thinking of ourselves as special in that way, and in order to come to a clear understanding of physical reality, and perhaps also psychological, we now realise that it often helps for us not to think of ourselves as in any way central. If we apply this to our appearance on this planet, we apparently ought to assume that we aren’t unusual, which suggests various things. For instance, since life appeared here after a very short period of time, it’s often thought that life must be present in all conditions where it can arise at all. As far as the evolution of intelligence and technology are concerned, on the one hand if we’re not special, one can expect aliens to be all over the Universe, but on the other, most of the time life has been on this planet it was in the form of microörganisms alone, so looking at the entire history of life so far, the way in which we’re not unusual may be in the sense that most life in the Universe is extremely simple compared to humans and also microscopic. The trouble is that we are a single example. All we know is that we’re here, and the fact that our Sun is yellow may not mean that in principle intelligent life can only evolve in yellow dwarf systems, but that it’s just unlikely in general, and we just happen to have a yellow dwarf Sun.

This next bit is based on this paper: https://arxiv.org/abs/2106.11207.

Kipping proposes the following solutions to the problem: life is rare on red dwarf planets; there is only a short period when complex life can evolve in the vicinity of these stars; suitable planets are rare.

Rarity of life might result from the initial instability of the stars leading to them causing all the water to evaporate from their planets, and assuming that water is essential to life, this would not enable life to evolve there, or survive if it arrived from somewhere else. Also, in our own system Jupiter protects Earth and other planets from cometary and asteroidal impacts and may also have corralled planetesimals into a comfortable distance from the Sun for Earth to form by a regular tug every orbit or every few orbits those objects made. If red dwarfs have nothing like Jupiter to do either, planets may not form at an appropriate distance or any that do form may be constantly pelted with asteroids and the like. Even so, and this is my observation, this could be a temporary phase while the system settles down into a more hospitable state, because the time might come when most of the débris has been cleared by colliding with planets, and after that life could appear, or evolve if it already had. That said, maybe that lies in the future for most red dwarf systems, and they have a lot of future compared to us. However, if life evolved in their systems about a hundredth as often, it would level the playing field and help explain why our Sun isn’t one of them. It would make it more of a coin-toss situation.

As previously observed, red dwarfs may not be particularly hospitable places for life. If flares and/or starspots are as pronounced as they often appear to be, it might simply be that they’re not good candidates for life to survive for long on. For instance, for a long time it was thought that Barnard’s Star was stable, but a flare were observed in 1998 which more than doubled the surface temperature and two more in 2019, the second one being sufficiently powerful to strip away Earth’s atmosphere within about fifteen million years if it occurred that regularly. Barnard’s Star does in fact have at least one planet, orbiting at about the mean distance Mercury does from the Sun, with about thrice Earth’s mass. With the same density, this would make it about 40% greater in diameter. Its existence is disputed, but it may not be in a good place. It also occurs to me, and I don’t know if this is true, that a planet with a much denser atmosphere than Earth’s, such as Venus, may become more habitable by having some of its atmosphere stripped away. The previously mentioned hotter phase early in such a star’s lifespan may also mean that life develops on planets somewhat further out but is then frozen out of existence as the star starts to settle down.

Kipping’s final suggestion is that planets orbiting within the habitable zone of red dwarfs could be rare. It’s easiest to detect planets orbiting brighter and larger stars, and for a red dwarf Barnard’s Star is unusually large, and most red dwarfs are unknown. The smaller stars are of course more common, and it may be that these small stars, which will last the longest, even up to ten thousand æons, don’t have any planets, although I personally don’t see why they wouldn’t have.

Kipping is clearly a very intelligent and well-educted guy, so I hesitate to come up with another explanation for our suffusion of yellow. Nonetheless I do have one, and perhaps strangely it starts with the Australian armed forces.

Some time ago, the Australian Army was having a problem with its uniforms, because many of them didn’t seem to fit very well, so they decided to come up with a small number of standard uniforms of various sizes. They embarked on a project of measuring various young adult males – inside leg, chest, arm length and the like – and found that there simply were no “average”, in the sense of being modal, sizes. Extending this further, it was found that the average Australian is female, thirty-seven years old, weighs 71.1 kg, is 161 centimetres tall, and has Australian parents but ancestry in Britain. This doesn’t sound like it’s a tall order to satisfy. There are, after all, twenty-five million Ozzies, so you’d think that just one of them at least would be exactly like this, but they aren’t. That’s a list of seven variables, so for them to be true of nobody in Australia the mean number of possibilities per variable would have to be about eleven. Another example might be having a fairly short mental list of characteristics for an ideal romantic partner. It may seem like it’s not much to ask, but in fact your chances of finding someone who perfectly satisfies that list diminishes very quickly with each added criterion.

Now apply this to planets with intelligent life on them. The average habitable planet might orbit a red dwarf star, have a mass about twice that of Earth’s, be 25% larger in diameter than this planet, have mainly shallow oceans, a dozen small continents, be closer to the inner edge of the habitable zone than Earth, be about six æons old, have a denser atmosphere than ours with more absolute amount of oxygen (but a smaller percentage). These are mainly the criteria for a “super-habitable” planet, that is, one which is even more suitable for life than Earth. Earth isn’t like this. Our Sun is brighter, larger and hotter, we’re smaller, have deeper oceans (nowadays – shallow seas used to be more common here though), have only half a dozen continents (again that number varies for reasons connected to shallow seas), is slightly colder than average, has a thinner atmosphere and less oxygen. Those are nine variables, some of which are continuous. If there are six hundred million habitable planets in the Galaxy, as has sometimes been estimated, each of them only needs to have about nine possibilities for such a planet to be unique. So perhaps the reason the Sun is yellow is that each habitable planet is an individual and has its own personality. Most of the planets might orbit red dwarfs, but each would be unique in its own way, and taken together there just is no such thing as the average habitable planet.

Does The Carrington Event Mean We’re All Doomed?

Photo by Pixabay on Pexels.com

There’s something alluring about a phenomenon or object named after at least one surname, though it’s better when there are two. ‘Look Around You’ knew about this when it mentioned the Beaumont Grille in the vegetable orchestra or whatever it was. The Helvetica Scenario is a bit different. If you didn’t already know what it was, the Carrington Event would be one of these. Here I run up against my usual problem of not knowing whether other people know stuff, so I’m going to run the risk of boring you all stiff by going into it.

The Carrington Event was a CME (coronal mass ejection: horrendous Sun kablooie, to paraphrase Calvin and Hobbes) occurring on the 1st and 2nd September 1859. It caused aurora australis to be visible as far north as Queensland and aurora borealis as far south as the Caribbean. This might be the kind of spectacular celestial display many people would kick themselves for having missed, but it had another more serious effect on human technology, namely the telegraphy network. Operators reported receiving electric shocks from their equipment, it caused pylons to emit sparks and it was even possible to send telegrams over wires with no technological source of current. It’s thought that the auroral event was associated with a previous CME which cleared a path for a second one against which Earth was then less protected. The magnetometer at Kew showed the strength of the event and the amateur astronomers Richards Carrington and Hodgson became the first people to observe a solar flare, hence the name. It’s possible that ice cores show traces of this event via concentrations of nitrates, although there can be other causes for this such as forest fires.

The Sun has a roughly eleven year cycle involving sunspots and other activity. Sunspots are cooler vortices on the visible solar surface which tend to proliferate and die down over this period, caused by a “winding up” of the magnetic field, and the latitude and quantity of the spots also varies. At the maxima, solar flares are more likely to occur, and the overall brightness of the Sun is slightly greater, which puzzles me a bit because sunspots are dimmer than the rest of the photosphere (surface). There’s also a longer cycle responsible for the likes of the Mediæval Warm Period, which lasted from 950-1100 CE. I don’t know if the Little Ice Age was connected. Climate change denialists have attempted to propagandise the public using this fluctuation, but in fact if you take it into consideration it shows that the overall temperature of the planet rose while the Sun was weaker and that the troposphere warms while the stratosphere cools because heat is being trapped close to the ground, whereas were it due to the Sun increasing its output it would heat the upper atmosphere more than the lower.

This was a geomagnetic storm. The Sun gives off a constant stream of charged particles called the solar wind. This fluctuates in intensity from time to time, and various events on the Sun drive these storms, such as CMEs. Because the magnetic field of the Sun is twisted during a solar maximum, spirals can form in the photosphere which then become realigned and the excess energy drives a large volume of more intense plasma away from the surface of the star at high speed. When it reaches our own magnetic field, it pushes it down on the sunlit side and increases the length of the tail on the dark side. This causes a similar tension in the magnetosphere here as it did on the Sun’s, and this has various effects. For instance, it can improve radio transmission by increasing the charge in the ionosphere, off which terrestrial radio waves can be bounced to increase their range, but also disrupt radio, damage electrical cables and cause power cuts and damage to satellites.

The Carrington Event is the strongest geomagnetic storm to affect Earth since it became possible to record such events reliably, but there have been earlier events which seem to have been similar. For instance, on the 4th November 1174 CE, a red light was seen across Europe and in December 940, red lights described as like ranks of soldiers in the sky were described in the annals of the Abbey of Sens. The difference, needless to say, is that the Middle Ages in Europe were not noted for their sophisticated electronic gadgetry, and unsurprisingly, religious interpretations were put onto these events. They were also probably not all associated with CMEs.

Back in the day, we had no electrical or electronic equipment. Although the filament lamp had been invented by 1859, said filament was made of platinum and the bulbs were ridiculously expensive and unreliable. The time for Joseph Swan’s patent was still a decade in the future, and telephones were even further off. As for mains power, that wouldn’t be happening anywhere until 1886, when Godalming got it. Hence we were more resilient back then. Life could just carry on as it always had with the minor detail of a few telegrams not getting through. It’s hardly even worth mentioning that this is no longer how things are.

If something like this happened today, it could destroy the internet, the GPS system and the cellular radio network. Moreover, if it was able to induce current in disconnected telegraphy systems, it wouldn’t be any good just to unplug everything, because delicate electronics could still be burnt out by the event. Two questions therefore arise. How often do they happen? How could we build in resilience to a world which has never encountered such a catastrophe when all the stuff is already out there?

In 2012, there was a somewhat similar event. On 23rd of July, a CME of about the same strength as the Carrington Event took place, crossing our orbit nine days away from the position of the planet. There are two solar observation satellites, STEREO-A and STEREO-B, one ahead of and one behind Earth. STEREO-A was able to observe and send back data from near the location, and was not damaged by the event, producing this I think famous image:

This doesn’t look like what one normally thinks of as a solar flare, which in my mind’s eye at least look more like this:

However, because the flare is heading directly for the satellite, it’s foreshortened and looks as if it surrounds the Sun. We’re seeing the Sun, or rather the blanked out bit where the Sun would be, through the CME. This is called a “halo” CME because it’s seen head-on, and that would be significant for us but there’s no real difference other than perspective. It’s interesting, incidentally, that this happened in 2012, that well-known apocalyptic year, because if we’d been just a little bit further along in our orbit or it had come out of a different bit of the Sun, we really would’ve experienced a major devastating event that year.

On 13th March 1989, a geomagnetic storm affected us strongly enough to have significant consequences. The auroræ almost reached the tropics, causing some to worry about nuclear war. Some satellites, and the space shuttle which was in orbit at that time, were also affected. Most notably, Quebec suffered a nine-hour powercut. It was affected more strongly due to the nature of the rock underneath the power lines and the fact that they were unusually long. Other power lines were protected because action was taken to ensure this, which is a bit reassuring.

The strongest storm of the twentieth century occurred from 13th-15th May 1921, causing fires and affecting undersea telegraph cables.

The risk per decade of a Carrington-level event is estimated at one in eight, clearly greater towards the maxima. They’re likely to induce currents in long metal structures, which as well as including powerlines and telecommunications cables also means gas and oil pipelines, so explosions and loss of fossil fuel supply seem likely to me but I’m not an expert of course. One suggestion for coping with them is to isolate transformers on the power grid and turn off satellites for the duration, which is several days. This would cause disruption in itself, but not as much as all the satellites and electrical devices being zapped out of existence permanently. A warning of some kind would be necessary and there would currently have to be enough of a workforce to facilitate this, meaning that currently this would be more dangerous during a holiday period. Aircraft would also be affected.

It’s important to note that CMEs don’t travel anywhere near the speed of light, meaning that satellites located at one of the points of balance between the Sun’s and Earth’s gravity, known as Langrange Points, would have time to transmit a warning of about an hour, and there are satellites located there for that very purpose. The specific risk to transformers is with step-up transformers, which overheat if there is a continuous supply of electrical current on the other side such as a hydroelectric power station, because the current has nowhere to go.

In fact, then, given forewarning it looks like we aren’t doomed after all, provided mitigating technologies are installed, and there are other risks such as flooding and hurricanes which are a more immediate threat. But that’s we humans. The Sun is a particularly stable star, and it’s in any case a given that we’ve come this far no matter how improbable it is because of the very large number of apparently habitable planets in the Universe. What isn’t clear is whether this is a potential Great Filter.

The Fermi Paradox is of course “where is everyone?”. There seem to be a very large number of suitable locations in the Universe for tool-using intelligence to appear and achieve space travel, but we are not aware of any intelligent aliens. Various explanations have been offered for this and one of them is stellar flares. We may have got lucky with our Sun being unusually stable. Over the past 140 years, apparently Sun-like stars fluctuate an average of five times as often as ours. If a civilisation developed electronics and became dependent upon them early enough, it might well not have put any such measures in place, and it’s possible that what’s happening is that civilisations are developing fine up until they reach twentieth century levels of technology, at which point they get damaged and have to start rebuilding from a much lower level. In fact, it could even be that the Sun is only unusually quiet right now and will later become more like a typical Sun-like star, with Carrington Events happening about once every twenty years or so.

Another issue here is with red dwarfs. Red dwarfs are the most common type of star and are cool and dim. However, they may be particularly suitable for Earth-like planets, because although such a planet would have to orbit so close to the star that there would be no relative rotation and it would be eternal day on one side and eternal night on the other, it turns out that the twilight zone would be at a comfortable temperature. However, red dwarfs are very often also “flare stars”. Proxima Centauri, Wolf 359 and Barnard’s Star are all flare stars. These are stars whose proportionate activity ramps up dramatically and frequently, which is not surprising considering their low mass: a flare on a red dwarf would be proportionately a much larger even than on the Sun. Because otherwise habitable planets are orbiting so close to them, this would be a much more destructive event which would also heat the planet up beyond habitable temperatures, at least to the twilight zone.

In conclusion then, the Carrington Event may not be as big a threat as it seemed at first. We’re aware of them and have taken steps to protect the infrastructure. However, at some point they may become much more frequent without warning, and they may have led to a situation where even widespread intelligent technological life finds it difficult to get beyond early industrial phase technology. In the apparently most suitable environments of all for life, CMEs may be so severe that they prevent the evolution of complex life even if that’s likely. Also, we may have just got lucky here, and lady luck has no memory, so that luck could end at any time.